02728naa a2200397 a 450000100080000000500110000800800410001902200140006002400540007410000200012824501430014826000090029152015840030065000180188465000120190265000290191465000210194365000110196465000120197565000200198765000260200765000130203365000110204665000100205765300110206765300190207865300190209765300150211670000180213170000190214970000180216870000170218670000200220370000200222377300870224319914212014-08-26       2014    bl uuuu     u00u1 u    #d  a0167-88097 ahttp://dx.doi.org/10.1016/j.agee.2014.01.0102DOI1 aLESSA, A. C. R.  aBovine urine and dung deposited on Brazilian savannah pastures contribute differently to direct and indirect soil nitrous oxide emissions.  c2014  aCattle ranching is one of the most important agricultural activities in Brazil. The impact of livestock onsoil N2O emissions in Brazil has only been assessed using a Tier 1 approach of the IPCC guidelines, as thereare no data available from field studies. Apart from the need for accumulating data for the developmentof proper direct N2O emission factors, we tested for possible differences between urine and dung as N2Osources and the difference in emissions between the dry and wet season. An area of Brachiaria brizantha atthe Embrapa Rice and Bean Centre in the Cerrado (central savannah) region (Goiás state) was subdividedinto plots where fresh cattle urine and dung were monitored for three consecutive periods (two in therainy and one in the dry season) for N losses, principally N2O emissions and NH3volatilization.15N-labelled urine N was used in the first monitoring period for an N balance study which indicated thatdenitrification and NH3volatilization were the most important processes for N loss. Percentages of N lostas N2O and as volatilized NH3were greater for urine than for dung. In addition, N losses as N2O in therainy season were much greater than during the dry season. Representing the Cerrado region and theextensive pasture systems common in this region, direct emission 0.007 g N2O?N g−1(0.7%) excreta N,well below the EF3PRPof 0.020 g N g−1(2%) used by IPCC for cattle N in excreta. The fraction of excreta Nlost as NH3of ∼15% was in line with the IPCC guidelines. Disaggregation of emission factors for excretatype is recommended.  aCattle manure  aExcreta  aGreenhouse gas emissions  aNitrogen balance  aBovino  aCerrado  aEsterco de gado  aFunção fisiológica  aMicção  aÓxido  aUrina  aCatlle  aCattle excreta  aGreenhouse gas  aN bbalance1 aMADARI, B. E.1 aPAREDES, D. S.1 aBODDEY, R. M.1 aURQUIAGA, S.1 aJANTALIA, C. P.1 aALVES, B. J. R.  tAgriculture, Ecosystems and Environment, Amsterdamgv. 190, p. 104-111, June 2014.